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asymmetry in ADHD patients

...fibres that connects the two hemispheres of the brain, contained slightly less tissue in those with ADHD. A similar study discovered small size discrepancies in the brain structures known as the caudate nuclei. In boys without ADHD, the right
caudate nucleus was normally about 3 percent larger than the left
caudate nucleus; this asymmetry was absent in boys with ADHD.

structures of the brain

Deep within the cerebral hemispheres, large gray masses of nerve cells, called nuclei, form components of the basal ganglia. Four basal ganglia can be distinguished: (1) the
caudate nucleus, (2) the putamen, (3) the globus pallidus, and (4) the amygdala. Phylogenetically, the amygdala is the oldest of the basal ganglia and is often referred to as the archistriatum; the globus pallidus is known...

...neurons that consists of two parts, the pars reticulata and the pars compacta. Cells of the pars compacta contain the dark pigment melanin; these cells synthesize dopamine and project to either the
caudate nucleus or the putamen, both of which are structures of the basal ganglia and are involved in mediating movement and motor coordination. These two structures, in addition to the globus...